Biochemistry M3. Use your experimental results to explain why enzymes are active over a relatively narrow range of temperature and pH. Explain why the rate of enzyme activity eventually reaches a limit as the substrate concentration increases.

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Just another essay for you all.

Enzymes perform as catalysts which are in charge of the rate of biochemical reactions. Each enzyme has an active site. This is when the enzyme and the substrate combine for a short period of time to create an enzyme substrate complex. The lock and key theory is in place to describe that the shape of the active site shares similarities to the substrate, which means when they meet they connect perfectly together. Enzymes have a narrow range of pH and temperature and this is due to the fact that they can be destroyed at extreme levels.

Within the experiment that I carried out, observing the effect of temperature on the enzyme amylase it was clear there was a connection between temperature and the time that it took for the enzyme to finish breaking down the starch. Between the temperatures 22°C and 50°C, the time changes decreased from 9 seconds to 2 seconds. Due to the temperature increases, this means that kinetic energy also increases which then increases the chances of enzyme and substrate colliding which also means that the rate of the reaction is quite fast. This is shown within the graph which represents the time taken for the starch to be broken down at 55°C was 7 seconds. This was because of the enzyme in this reaction becoming denatured due to the temperature being so high. This is because the hydrogen bonds holding the enzyme together are broken, therefore takes longer for the enzyme to function.

pH levels can also impact enzyme activity. When the pH is increased, the amount of enzyme substrate complex will also be increased until the peak pH is discovered. The peak pH level of an enzyme is 7. The bonds that hold the enzyme can be denatured. This is due to the breaking which decreases the rate of reaction as the enzyme no longer functions.

The second experiment I carried out shows the rate of enzyme activity reaches a limit while the substrate concentration rises. The percentage of hydrogen peroxide is increased; this had an effect on the way that the substrate concentration affected the capability of the enzyme catalase and increased the rate of the reaction. This is shown within the results of the graph as the increased rate of the reactions is steady. When the rare if the reactions increase, this is caused by the increase of substrates within the solution, the chances of the enzyme and the substrate colliding in the active site are high. The rate of the reaction will eventually get to a stage where it will decrease due to the tolerance levels. The enzymes are no longer able to react any faster.

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